Technical 126 Bis FIRE engine conversion.

[elbandito472]

Hi all, well after a 3 year rollercoaster love affair with my 126 Bis, over the last few months i have completed a FIRE 999 engine conversion. Just a few small loose ends to tidy up looks wise, but all legal and registered as a 999cc and MOT'd. After 30 miles of testing its developed a misfire so am currently in the process of sorting that. Is anyone interested in me posting pics and info on here? I know the engine conversion subject is rather contentious but i can confirm that it can be completed sensibly and legally.

 

[Fiatcinquecento]

Yes please, was looking into this myself, would love some photos!!!

 

[elbandito472]

Ok cool. I'll put something together over the next week. Although its not necessarily 'easy', its easier than you might think.

 

[elbandito472]

Firstly i purchased an adaptor plate on eBay. Then i hunted for a donor car. I've had a lot of experience with the FIRE engine so after the nightmare i had with the Bis (2 years rebuilding the engine including fitting Abarth internals and egnineering improvements, 11 miles into the first drive and the NEW rear crank bearing failed...it actually crumbled to pieces due to a manufacturing flaw. I was so upset that i garaged the car for 6 months.), i decided to fit a FIRE motor to avoid buying more faulty parts.
I didnt want to fit a 999, 1108 or 1242 at first as i was concerned about the torque through the gearbox, after all, the priority of this build was reliability not performance. However after struggling to locate a complete and running 750 Panda that would be a suitable donor (they were all to nice to break and also expensive), i began searching for a 999cc which is obviously far more common and more available as a carburettor power unit which lends itself to the age and style of the 126 quite nicely. I wanted a running car so i could try the engine out before the build. I found a 1990 UNO with 80k on the clock for a good price. I trailered it home from purchase.....and im so glad i did. The engine ran beautifully, but the front o/s wheel was spaced about 10mm wider than the left, the rear turrets had rust burst under the carpet trim and i counted 4 fuel leaks including petrol oozing through the layers of rust in the tank! It had just passed an 'MOT' too....anyway, the engine was a gem. And so began the build:

 

[elbandito472]

The adaptor plates are available for the aircooled 126 models so the quickest and easiest course seemed to be to purchase an aircooled bellhousing and fit that to the Bis gearbox. I bought a used one for £20 (again, thanks ebay). In these pics you can see the adaptor plate fitted to the bellhousing and then all three parts together.

 

[elbandito472]

The adaptor plate is a good template to add to. We added a top fixing point (under the thermostat) to the plate to support the top of the bell housing and then welded thin fillets all the way round the plate to protect the flywheel when fitted. The original aircooled lower flywheel cover also fits with this install. As an aside, the flywheel needed about 50 thou skimmed off the rear in order to clear the adaptor plate. I'm lucky, as although i am a mechanic my father is an engineer so he has done the bulk of the fabrication.

 

[elbandito472]

Bell housing fitting

 

[elbandito472]

Cutting the chassis and first trial install minus flywheel and clutch.

 

[elbandito472]

Measurements were taken before and after cutting and the chassis didn't even spring a millimetre. Clearly the distributor didnt fit, so we braced the middle of the car with a steel tube across the rear of the seat line, also down into the box section either side of the dizzy. Next we cut (after taking measurements) the box section that was fouling the dizzy and welded in some channelling. This left plenty of room for the dizzy and for an inspection panel.

 

[elbandito472]

Next came the design of the rear subframe. There is lots of inspiration available on the net. I wanted this project to be reasonably quick and easy. Also i was aware of weight factors. I also wanted the project to include as many standard parts as possible (cables/mounts/hoses etc), whether 126 or Uno i didn't mind but i wanted to stay away from custom parts as much as possible to aid with future maintenance.

 

[elbandito472]

We boxed the open rear chassis member ends and machined up some threaded inserts which were welded in to enable the subframe to act as a brace.

 

[elbandito472]

Here you can see the braces on the subframe and the firewall.

 

[elbandito472]

Here you can see the braces on the subframe and the firewall installed

 

[elbandito472]

Top engine cover and sound deadening

 

[elbandito472]

Subframe painted, numberplate, foglight etc. this is where im up to to date.

 

[elbandito472]

The engine developed a bad misfire after about 30 miles. After some fault finding it transpired to be that the old cambelt had jumped 2 teeth. I had a cambelt kit in stock so replaced it and also fitted a new dizzy as the auto advance was badly worn and seized. Id planned to change the belt over winter after putting in some test miles. However since this issue we are up to 140 miles without major issues. Fingers crossed.... From having the engine removed from the Uno to having it fitted in the 126 able to drive took about 3 months of free time. If anyone has any questions, please feel free to ask. I've tried to cover the 'bulky' stuff in this thread, but there was plenty of other head scratching, e.g. cooling system, exhaust, wiring and admin: DVLA etc. Mega thanks to my father for his expertise, time and advice and my wife for putting up with me through the whole saga

 

[Fiatcinquecento]

This build has inspired me massively, I have an identical car to yours and all, with the same problem, buggured engine, what did you do for cooling, front mount or bis rad?
Really impressed

 

[thepuddlejumper]

Hi, you mentioned DVLA, how did you get on and what did they require?

Ralph

 

[gadge]

What a fantastic project! The 126 is and always will be a difficult car to do an engine conversion on due to its space resrictions. Many, many poor attempts using bike and car engines usually come to nothing or badly executed to the point of being Undrivable. I've seen similar FIRE engined conversions before (but never in a BIS!) and I firmly believe that the FIRE is one of a handful of engines that can realisily work as it just about fits in there in the back (mid mounted ones are just a no-no for me). You've done a fantastic job and I'm well impressed that you have kept it very tasteful with the bumpers and wheels and resisted the urge to widen or modify the bodywork unnecessarily.

Great job

 

[Timeliner]

Great car. Love it.

As an aside, I know at some point Fiat had a prototype front engine/front wheel drive 126 up and running. Has anyone tried, or does anyone know of anyone doing such a thing to their own 126?